The invention relates generally to the dispensing of adhesive tissue sealants and other liquid preparations, including those requiring mixing immediately prior to use.
A variety of techniques have been used to bond or seal living tissue. For example, different types of tissues have been mechanically bound or sealed with a number of procedures, materials and methods including sutures, staples, tapes and bandages. In some applications, these materials are made of absorbable materials that are intended to bond and/or seal tissue as it heals and then to be absorbed over a period of time.
A recent addition to the techniques that can be used is application of an absorbable adhesive sealant composition to bond and/or seal tissue. The adhesive composition is readily formed from a two component mixture that includes a first part of a cross-linking agent and a second part of a protein, preferably a serum protein such as albumin. When the two parts of the mixture are combined, the mixture is initially liquid. The combined mixture then cures in vivo on the surface of tissue to give a substantive composition that securely bonds to the tissue. A more complete discussion can be found in coassigned U.S. Pat. No. 5,583,114, xe2x80x9cADHESIVE SEALANT COMPOSITION,xe2x80x9d to Barrows et al, the entire contents of which are hereby incorporated by reference.
This material is most conveniently dispensed from a dual syringe which maintains the two parts strictly separate until just before they are dispensed onto the tissue because the reaction time to the forming of the finished sealant is quite fast. Copending and coassigned U.S. application Ser. No. 09/524,141, filed Mar. 10, 2000, Wirt et al., the entire contents of which are hereby incorporated by reference, discloses a particularly suitable dual syringe that uses twin carpules to contain the liquid components. When the user presses on the pistons the liquid components are pressurized into flow passageways and into a dispensing tip. The nozzle of the dual syringe and the structure of the dispensing tip keep the two components separate until the proper time for mixing.
A limitation that remains on the use of this sealant and its dispenser is the short, straight dispensing tip is sometimes inadequate for working in the confined spaces of a surgical site. An angled tip would often be more suitable, but an angled tip could not be inserted into the long, narrow cannulas which are often used these days to access body organs with minimum incisions.
The present invention provides a dispensing tip having two rigid sections connected together by a flexible section. Preferably, although bendable, the flexible section has enough resilience that in the absence of external force the two rigid sections are held at a predictable angle to one another. In this way manual dispensing into hard to reach places during surgery is facilitated. However, if it is suddenly decided that the dispensing through a cannula into a largely closed body cavity is desired, a flip of the wrist straightens the distal rigid section enough to allow the dispensing tip to be inserted into the straight cannula. When the distal rigid section emerges from the far end of the cannula inside the patient""s body, it resiliently returns to its convenient angled orientation.
More specifically, the dispensing tip has a first rigid section having at least one lumen passing therethough. Preferred embodiments, particularly for the composition of U.S. Pat. No. 5,583,114, have two lumens that keep the components of the composition separate throughout substantially all of the length of the first rigid section. The dispensing tip also has a flexible section attached to the first rigid section. Distal to the flexible section is a second rigid section attached to the flexible section. This second rigid section has an opening for dispensing material conducted through the lumen. Preferred embodiments include a static mixer within at least a portion of the second rigid section that the components encounter before reaching the opening. A static mixing element may optionally appear within the flexible section, depending on the length chosen for the second rigid section, and depending on how much mixing the solution being dispensed requires.
In preferred embodiments, the dispensing tip is such that the flexible section has a preset bend so as to urge the first and the second rigid sections towards a preset angle to one another. For many surgical purposes, an angle of between about 20 and 45 degrees will suit the surgeon""s need best. In particular, an angle of about 30 degrees is considered particularly desirable. However, for some specialized purposes, particularly in surgery to repair a pneumothorax, a much sharper bend, even as much as 180 degrees will occasionally be useful to e.g. spray the adhesive sealant on a hard-to-reach point on the backside of the lung.
Other features and advantages of the invention will be apparent from the following description and drawings, and from the claims.